Psychologists say more research into deliberately lit fires could help to stop arsonists and pyromaniacs from reoffending.

The comment comes in response to a number of suspicious fires across Western Australia and the arrest of a volunteer firefighter from the south-west accused of arson.

Clinical psychologist Steve Jobson said while research was routinely done into domestic violence offenders, more needed to be done on 'firesetting', a term used to describe arson and pyromania.

He said about 50 per cent of bushfires were deliberately lit or suspicious and about 30 per cent of the people responsible would reoffend.

"Rather than just simply seeing this behaviour as abhorrent, as something which is potentially dangerous and life threatening, we also need to look at how we can help prevent this in the future, how we can assist this person from reoffending," he said.

"Around 30 per cent of fire setters will commit further acts of setting fires, now that's quite a high amount, so if we can find out why they're doing this we can introduce the necessary and appropriate intervention, counselling treatment, rehabilitation."

You have no doubt been hearing a lot about the Paris Agreement and know that it pertains to climate change, but are too embarrassed at this stage to ask for an overall explanation of what it's all about.